Organic light-emitting display device and method of fabricating the same

ABSTRACT

The present invention relates to an organic light-emitting display device and a method of fabricating the same. The device may include a base substrate, a thin-film transistor disposed on the base substrate, an organic light-emitting device including a first electrode connected to the thin-film transistor, an organic pattern disposed on the first electrode, and a second electrode disposed on the organic pattern. The device further includes an auxiliary electrode including a connection part and a non-connection part, the connection part being connected to the second electrode. The width of the connection part may be less than that of the non-connection part, when measured in the direction perpendicular to a current flow.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a Divisional of U.S. patent application Ser. No.14/055,548, filed on Oct. 16, 2013, and claims priority from and thebenefit of Korean Patent Application No. 10-2013-0064122, filed on Jun.4, 2013, each of which is hereby incorporated by reference for allpurposes as if fully set forth herein.

BACKGROUND

Field

Exemplary embodiments of the present disclosure relate to an organiclight-emitting display device configured to prevent a voltage drop fromoccurring and a method of fabricating the same.

Discussion of the Background

Conventionally, an organic light-emitting display device includes athin-film transistor substrate, an opposite substrate, and a pluralityof organic light-emitting devices disposed between the thin-filmtransistor substrate and the opposite substrate. In the organiclight-emitting device, an organic layer is provided on an anodeelectrode, which may be partially exposed by a pixel defining layer, anda cathode electrode is provided on the organic layer. During anoperation of the organic light-emitting device, holes and electrons areinjected into the organic layer from the anode and cathode electrodesand recombined with each other to produce excitons. The excitons mayfall from the excited state to the ground state, thereby emitting lighthaving the same energy as a difference in energy between the excited andground states.

If the cathode electrode is a thin metal layer, a voltage applied to thepixel may vary depending on its position. For example, due to a voltagedrop, there is a difference in voltage between regions adjacent anddistant to a voltage input node.

Such a voltage difference may lead to deterioration in light-emittingefficiency of the organic light-emitting device.

The above information disclosed in this background section is only forenhancement of understanding of the background of the disclosed subjectmatter and therefore may contain information that does not form any partof the prior art nor what the prior art may suggest to a person ofordinary skill in the art.

SUMMARY

Exemplary embodiments of the present disclosure provide an organiclight-emitting display device configured to prevent a voltage drop fromoccurring.

Exemplary embodiments of the present disclosure also provide a method offabricating the organic light-emitting display device.

Additional features of the present disclosure will be set forth in thedescription which follows, and in part will be apparent from thedescription, or may be learned by practice of the disclosed subjectmatter.

Exemplary embodiments of the present disclosure disclose an organiclight-emitting display device including a base substrate, a thin-filmtransistor disposed on the base substrate, and an organic light-emittingdevice including a first electrode connected to the thin-filmtransistor, an organic pattern disposed on the first electrode, and asecond electrode disposed on the organic pattern. The organiclight-emitting display device further includes an auxiliary electrodeincluding a connection part and a non-connection part. The connectionpart is connected to the second electrode. A width of the connectionpart is less than a width of the non-connection part.

Exemplary embodiments of the present disclosure also disclose an organiclight-emitting display device including a base substrate, a thin-filmtransistor disposed on the base substrate, an organic light-emittingdevice including a first electrode connected to the thin-filmtransistor, an organic pattern disposed on the first electrode, and asecond electrode disposed on the organic pattern. The organiclight-emitting display device further includes an auxiliary electrodeincluding a connection part and a non-connection part. The connectionpart is connected to the second electrode. The connection part and thenon-connection part have different resistances from each other.

Exemplary embodiments of the present disclosure also disclose a methodof fabricating an organic light-emitting display device. The methodincludes forming a thin-film transistor on a base substrate, forming afirst electrode connected to the thin-film transistor and an auxiliaryelectrode spaced apart from the first electrode. The auxiliary electrodeincludes a connection part and a non-connection part. The method furtherincludes forming a pixel defining layer exposing portions of the firstelectrode and portions of the connection part, forming an organic layeron the first electrode, the connection part, and the pixel defininglayer; patterning the organic layer to form an organic pattern; andforming a second electrode on the organic pattern and the pixel defininglayer. The forming of the organic pattern includes applying an electricpower to the auxiliary electrode to produce heat from the connectionpart and removing a portion of the organic layer adjacent to theconnection part using the heat.

It is to be understood that both the foregoing general description andthe following detailed description are exemplary and explanatory and areintended to provide further explanation of the disclosed subject matteras claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the disclosed subject matter and are incorporated inand constitute a part of this specification, illustrate embodiments ofthe disclosed subject matter, and together with the description serve toexplain the principles of the disclosed subject matter.

FIG. 1 is a schematic circuit diagram illustrating an organiclight-emitting display device according to exemplary embodiments of thepresent disclosure.

FIG. 2 is a sectional view illustrating a driving thin-film transistorand an organic light-emitting device in one of the pixels of FIG. 1according to exemplary embodiments of the present disclosure.

FIG. 3 is a plan view illustrating the auxiliary electrode of FIG. 2according to exemplary embodiments of the present disclosure.

FIGS. 4, 5, 6, 7, and 8 are sectional views illustrating a method offabricating the organic light-emitting display device of FIGS. 1, 2, and3 according to exemplary embodiments of the present disclosure.

FIG. 9 is a sectional view illustrating an organic light-emittingdisplay device according to exemplary embodiments of the presentdisclosure.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS

Exemplary embodiments of the disclosed subject matter are described morefully hereinafter with reference to the accompanying drawings. Thedisclosed subject matter may, however, be embodied in many differentforms and should not be construed as limited to the exemplaryembodiments set forth herein. Rather, the exemplary embodiments areprovided so that this disclosure is thorough and complete, and willconvey the scope of the disclosed subject matter to those skilled in theart. In the drawings, the size and relative sizes of layers and regionsmay be exaggerated for clarity. Like reference numerals in the drawingsdenote like elements.

It will be understood that when an element or layer is referred to asbeing “on”, “connected to”, or “coupled to” another element or layer, itcan be directly on, connected, or coupled to the other element or layeror intervening elements or layers may be present. In contrast, when anelement is referred to as being “directly on”, “directly connected to”,or “directly coupled to” another element or layer, there are nointervening elements or layers present. As used herein, the term“and/or” includes any and all combinations of one or more of theassociated listed items. It may also be understood that for the purposesof this disclosure, “at least one of X, Y, and Z” can be construed as Xonly, Y only, Z only, or any combination of two or more items X, Y, andZ (e.g., XYZ, XYY, YZ, ZZ).

It will be understood that, although the terms “first”, “second”, etc.may be used herein to describe various elements, components, regions,layers and/or sections, these elements, components, regions, layersand/or sections should not be limited by these terms. These terms areonly used to distinguish one element, component, region, layer orsection from another element, component, region, layer or section. Thus,a first element, component, region, layer or section discussed belowcould be termed a second element, component, region, layer or sectionwithout departing from the teachings of exemplary embodiments of thepresent disclosure.

Spatially relative terms, such as “beneath”, “below”, “lower”, “above”,“upper”, and the like, may be used herein for ease of description todescribe one element or feature's relationship to another element(s) orfeature(s) as illustrated in the figures. It will be understood that thespatially relative terms are intended to encompass differentorientations of the device in use or operation in addition to theorientation depicted in the figures. For example, if the device in thefigures is turned over, elements described as “below” or “beneath” otherelements or features would then be oriented “above” the other elementsor features. Thus, the exemplary term “below” can encompass both anorientation of above and below. The device may be otherwise oriented(rotated 90 degrees or at other orientations) and the spatially relativedescriptors used herein interpreted accordingly.

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting of exemplaryembodiments. As used herein, the singular forms “a,” “an”, and “the” areintended to include the plural forms as well, unless the context clearlyindicates otherwise. It will be further understood that the terms“comprises”, “comprising”, “includes” and/or “including,” if usedherein, specify the presence of stated features, integers, steps,operations, elements and/or components, but do not preclude the presenceor addition of one or more other features, integers, steps, operations,elements, components and/or groups thereof.

Example embodiments of the disclosed subject matter are described hereinwith reference to cross-sectional illustrations that are schematicillustrations of idealized embodiments (and intermediate structures) ofthe disclosed subject matter. As such, variations from the shapes of theillustrations as a result, for example, of manufacturing techniquesand/or tolerances, are to be expected. Thus, example embodiments of thedisclosed subject matter should not be construed as limited to theparticular shapes of regions illustrated herein but are to includedeviations in shapes that result, for example, from manufacturing. Forexample, an implanted region illustrated as a rectangle may have roundedor curved features and/or a gradient of implant concentration at itsedges rather than a binary change from implanted to non-implantedregion. Likewise, a buried region formed by implantation may result insome implantation in the region between the buried region and thesurface through which the implantation takes place. Thus, the regionsillustrated in the figures are schematic in nature and their shapes arenot intended to illustrate the actual shape of a region of a device andare not intended to limit the scope of the disclosed subject matter.

Unless otherwise defined, all terms (including technical and scientificterms) used herein have the same meaning as commonly understood by oneof ordinary skill in the art to which this disclosed subject matterbelongs. It will be further understood that terms, such as those definedin commonly-used dictionaries, should be interpreted as having a meaningthat is consistent with their meaning in the context of the relevant artand will not be interpreted in an idealized or overly formal senseunless expressly so defined herein.

Hereinafter, exemplary embodiments of the present disclosure will bedescribed in detail with reference to the accompanying drawings.

FIG. 1 is a schematic circuit diagram illustrating an organiclight-emitting display device according to exemplary embodiments of thepresent disclosure.

Referring to FIG. 1, an organic light emitting display device mayinclude a display substrate DS with a display portion 10 configured todisplay an image, a scan driver 20, and a data driver 30.

The scan driver 20 and the data driver 30 may be electrically connectedto the display portion 10 through signal lines including scan lines SL₁,SL₂, and SL_(n), (n being any whole number greater than 1), data linesDL₁, DL₂, and DL_(m), (m being any whole number greater than 1), andpower supply lines VL.

For example, the scan driver 20 may be electrically connected to thedisplay portion 10 through a plurality of the scan lines SL₁, SL₂, andSL_(n). The scan driver 20 may be configured to send scan signals to thedisplay portion 10 through the scan lines SL₁, SL₂, and SL_(n), whichmay be provided on the display substrate DS to extend in a firstdirection.

The data driver 30 may be electrically connected to the data lines DL₁,DL₂, and DL_(m). Accordingly, the data driver 30 may be electricallyconnected to the display portion 10 through a plurality of the datalines DL₁, DL₂, and DL_(m). The data driver 30 may be configured to senddata signals to the display portion 10 through the data lines DL₁, DL₂,and DL_(m).

The data lines DL₁, DL₂, and DL_(m) may extend along a differentdirection (e.g., a second direction) from the scan lines SL₁, SL₂, andSL_(n). For example, the data lines DL₁, DL₂, and DL_(m) may cross(e.g., may be perpendicular to) the scan lines SL₁, SL₂, SL_(n).

The power supply lines VL may apply an electric power to the displayportion 10. The power supply lines VL may be disposed to cross the datalines DL₁, DL₂, and DL_(m) and/or the scan lines SL₁, SL₂, SL_(n).

The display portion 10 may include a plurality of pixels PX. Each of thepixels PX may be electrically connected to the corresponding one of thedata lines DL₁, DL₂, and DL_(m), the corresponding one of the scan linesSL₁, SL₂, and SL_(n), and the corresponding one of the power supplylines VL. Each of the pixels PX may include a switching thin filmtransistor TRs, a driving thin film transistor TRd, a capacitor C, andan organic light emitting device (OLED). The transistors TRs and TRd mayfunction as switching elements that operate according to a data signaltransmitted through the data lines DL₁, DL₂, and DL_(m) to a pixel and agate signal transmitted through the scan lines SL₁, SL₂, SL_(n). Each ofthe transistors TRs and TRd may include a gate electrode, a sourceelectrode, a drain electrode, and a channel region between source anddrain regions corresponding to the source and drain electrodes,respectively.

The switching thin film transistor TRs may be connected to thecorresponding one of the scan lines SL₁, SL₂, and SL_(n), and thedriving thin film transistor TRd may be connected to the correspondingone of the data lines DL₁, DL₂, and DL_(m). Each of the switching anddriving thin film transistors TRs and TRd may include a semiconductoractive layer, a gate electrode electrically separated from thesemiconductor active layer, and source and drain electrodes connected tothe semiconductor active layer.

The scan signal from the scan driver 20 and the data signal from thedata driver 30 may be transmitted to each of the pixels PX through thescan lines SL₁, SL₂, and SL_(n) and the data lines DL₁, DL₂, and DL_(m).In each of the pixels PX, the switching thin film transistor TRs may beconfigured to control a switching operation of the driving thin filmtransistor TRd in response to the scan signal and the data signalapplied thereto. The driving thin film transistor TRd may be configuredto supply a driving electric current, which corresponds to the datasignal, to the organic light emitting device OLED. The supplied drivingelectric current may be used to generate light in the organic lightemitting device OLED.

A capacitor C may be provided between the drain electrode of theswitching thin film transistor TRs and the gate electrode of the drivingthin film transistor TRd. The capacitor C may also be connected betweenthe drain and gate electrodes of the driving thin film transistor TRd.Due to the presence of the capacitor C, the data signal may be appliedto the gate electrode of the driving thin film transistor TRd even whenthe switching thin film transistor TRs is in an off state.

Although not shown in detail, the organic electro luminescence displaydevice may also include at least one thin film transistor and at leastone capacitor to improve threshold voltage characteristics of thedriving thin film transistor TRd.

Hereinafter, structures of the organic light-emitting display devicewill be described in detail with reference to FIGS. 2 and 3. Further, adirection oriented from a base substrate toward the driving thin filmtransistor TRd or the organic light emitting device OLED will bereferred to as an “upper direction”.

FIG. 2 is a sectional view illustrating a driving thin-film transistorTRd and an organic light-emitting device OLED in one of the pixels ofFIG. 1. FIG. 3 is a plan view illustrating the auxiliary electrode ofFIG. 2.

Referring to FIGS. 2 and 3, an organic light-emitting display device mayinclude the driving thin-film transistor TRd, an organic light-emittingdevice OLED, and an auxiliary electrode 170 disposed on a base substrate100. The organic light-emitting device OLED may be connected to thedriving thin-film transistor TRd.

The base substrate 100 may include a transparent insulating material andbe optically transparent. The base substrate may be a rigid-typesubstrate or a flexible-type substrate. The rigid-type substrate may beone of a glass substrate, a quartz substrate, a glass ceramicssubstrate, and a crystalline glass substrate. The flexible-typesubstrate may be one of a film substrate and a plastic substrateincluding an organic polymer material. The base substrate may be formedof a material that can be prevented from being deteriorated by heat.

The driving thin-film transistor TRd may be disposed on the basesubstrate 100. The driving thin-film transistor TRd may include a gateelectrode GE, a semiconductor active layer SA electrically separatedfrom the gate electrode GE, and source and drain electrodes SE and DEconnected to the semiconductor active layer SA.

For example, the gate electrode GE may be provided on the base substrate100 and may include a conductive material.

A gate insulating layer 120 may be provided on the gate electrode GE andthe base substrate 100 to cover the gate electrode GE. The gateinsulating layer 120 may be provided to separate the gate electrode GEelectrically from the semiconductor active layer SA. The gate insulatinglayer 120 may include silicon oxide (SiO₂) and/or silicon nitride(SiNx).

The semiconductor active layer SA may be provided on the gate insulatinglayer 120 which may be overlapped with the gate electrode GE. Thesemiconductor active layer SA may include one of amorphous silicon(a-Si), poly silicon (p-Si), and oxide semiconductors. Further, thesemiconductor active layer SA may include a channel region, which may beoverlapped with the gate electrode GE, and source and drain regions,which are located at both sides of the channel region and doped withimpurities. The oxide semiconductors may contain at least one of Zinc(Zn), Indium (In), Gallium (Ga), Tin (Sn), or mixtures thereof. Forexample, the oxide semiconductors may include indium-gallium-zinc oxide(IGZO).

Although not shown, if the semiconductor active layer SA includes one ofthe oxide semiconductors, a light-blocking layer may be provided on orunder the oxide semiconductor active layer SA to prevent light frombeing incident to the oxide semiconductor active layer SA.

The source electrode SE and the drain electrode DE may be connected tothe source and drain regions, respectively, of the semiconductor activelayer SA. The source electrode SE and the drain electrode DE may includeone of copper, copper alloy, aluminum, and aluminum alloy.

In some cases as shown in FIG. 2, the driving thin-film transistor TRdis provided to have a bottom gate structure, but exemplary embodimentsof the present disclosure may not be limited thereto. For example, thedriving thin-film transistor TRd may be provided to have a top gatestructure.

Further, although not shown in FIG. 2, an ohmic contact layer may beprovided between the source region and the source electrode SE andbetween the drain region and the drain electrode DE. The ohmic contactlayer may contribute to improve an electric connection property betweenthe source region and the source electrode SE and between the drainregion and the drain electrode DE.

In some cases, a buffer layer 110 may be provided between the basesubstrate 100 and the driving thin-film transistor TRd. The buffer layer110 may be one of a silicon oxide layer and a silicon nitride layer ormay have a multi-layered structure including the silicon oxide layer andthe silicon nitride layer. The buffer layer 110 may prevent impuritiesin the base substrate 100 from being diffused into the driving thin-filmtransistor TRd and the organic light-emitting device OLED. For example,due to the presence of the buffer layer 110, it is possible to preventmoisture and oxygen from soaking into the driving thin-film transistorTRd and the organic light-emitting device OLED. The buffer layer 110 maybe configured to provide a planarized top surface.

A protection layer 130 may be provided on the base substrate 100 withthe driving thin-film transistor TRd. For example, the protection layer130 may be disposed on the driving thin-film transistor TRd. Theprotection layer 130 may be provided to have a contact hole CH partiallyexposing the drain electrode DE.

The protection layer 130 may include at least one layer including aninorganic protection layer and an organic protection layer disposed onthe inorganic protection layer. The inorganic protection layer mayinclude at least one of silicon oxide and silicon nitride. The organicprotection layer may include at least one of acryl, polyimide (PI),polyamide (PA) and benzocyclobutene (BCB). The organic protection layermay be transparent and flexible, and thus, it may serve as aplanarization layer reducing unevenness of an underlying structure.

The organic light-emitting device OLED and the auxiliary electrode 170may be disposed on the protection layer 130. The organic light-emittingdevice OLED may include the first electrode 140 connected to the drainelectrode DE, the organic pattern 150 disposed on the first electrode140, and the second electrode 160 disposed on the organic pattern 150.

At least one of the first and second electrodes 140 and 160 may be atransmissive electrode. For example, in the case where the organic lightemitting display device is a bottom-emission type display device, thefirst electrode 140 may be a transmissive electrode, while the secondelectrode 160 may be a reflective electrode. In the case where theorganic light emitting display device is a top-emission type displaydevice, the first electrode 140 may be a reflective electrode, while thesecond electrode 160 may be a transmissive electrode. In the case wherethe organic light emitting display device is a dual emission typedisplay device, both of the first electrode 140 and the second electrode160 may be transmissive electrodes.

One of the first electrode 140 and the second electrode 160 may be ananode electrode, and the other a cathode electrode.

The description that follows will refer to exemplary embodiments of thepresent disclosure in which the first electrode 140 and the secondelectrode 160 are used as a transparent anode electrode and a reflectivecathode electrode, respectively.

The first electrode 140 may be disposed on the protection layer 130 andbe connected to the drain electrode DE through the contact hole CH. Thefirst electrode 140 may include a transparent conductive oxide having awork-function higher than that of the second electrode 160. For example,the first electrode 140 may include one of indium tin oxide (ITO),indium zinc oxide (IZO), aluminum zinc Oxide (AZO), gallium doped zincoxide (GZO), zinc tin oxide (ZTO), gallium tin oxide (GTO), and fluorinedoped tin oxide (FTO).

The first electrode 140 may be partially exposed by a first opening OP1of a pixel-defining layer PDL. The pixel-defining layer PDL may includean organic insulating material. For example, the pixel-defining layerPDL may include at least one of polystylene, poly methyl methacrylate(PMMA), polyacrylonitrile (PAN), polyamide, polyimide, polyarylether,heterocyclic polymer, parylene, fluorine series polymer, epoxy resin,benzocyclobutene series resin, siloxane series resin, or silane.

The second electrode 160 may include at least one of materials (e.g.,Molybdenum (Mo), Tungsten (W), Silver (Ag), Magnesium (Mg), Aluminum(Al), Platinum (Pt), Palladium (Pd), Gold (Au), Nickel (Ni), Neodymium(Nd), Iridium (Ir), Chromium (Cr), Lithium (Li), Calcium (Ca), andalloys thereof), having a work-function that is smaller than the firstelectrode 140. In addition, the auxiliary electrode 170 may be disposedon the protection layer 130 and connected to the second electrode 160 toprevent a voltage drop problem of the second electrode 160 fromoccurring.

The organic layer 150 may be disposed on the first electrode 140 exposedby the pixel-defining layer PDL. The organic layer 150 may include atleast one emitting layer EML and, in general, may have a multi-layeredstructure. For example, the organic layer 150 may include a holeinjection layer HIL, a hole transport layer HTL, the emitting layer EML,a hole blocking layer HBL, an electron transport layer ETL, and anelectron injection layer EIL. The hole transport layer HTL may have highhole mobility and be configured to suppress movement of electrons thatare not combined in the emitting layer EML, thereby increasingprobability of recombination between holes and electrons. In theemitting layer EML, the injected electrons and holes may be re-combinedwith each other to emit light. The hole blocking layer HBL may beconfigured to suppress holes, which are not combined with electrons inthe emitting layer EML, from moving. The electron transport layer ETLmay be configured to move electrons to the emitting layer EMLefficiently. The emitting layer of the organic layer 150 may beconfigured to emit/pass one of red, green, blue and white lights, butexemplary embodiments of the present disclosure may not be limitedthereto. For example, the emitting layer of the organic layer 150 may beconfigured to emit/pass one of magenta, cyan, and yellow lights.

The organic layer 150 may not be provided between the auxiliaryelectrode 170 and the second electrode 160, and this makes it possibleto improve an electric connection property between the auxiliaryelectrode 170 and the second electrode 160. The auxiliary electrode 170may be connected to the second electrode 160, thereby preventing avoltage drop from occurring in the second electrode 160.

The auxiliary electrode 170 may be provided on the protection layer 130to be spaced apart from the first electrode 140, and the auxiliaryelectrode 170 may include the same material as the first electrode 140.A portion of the auxiliary electrode 170 may be exposed by a secondopening OP2 of the pixel defining layer PDL.

The auxiliary electrode 170 may include a connection part CP and atleast one non-connection part NCP. The connection part CP may refer to aregion in contact with the second electrode 160, and the non-connectionpart NCP may refer to a region that is not in contact with the secondelectrode 160.

In addition, when measured in the direction perpendicular to a currentflow, a width W1 of the connection part CP may be less than a width W2of the non-connection part NCP.

FIGS. 4, 5, 6, 7, and 8 are sectional views illustrating a method offabricating the organic light-emitting display device of FIGS. 1, 2, and3.

Referring to FIG. 4, the buffer layer 110 may be formed on the basesubstrate 100. The buffer layer 110 may be one of a silicon oxide layerand a silicon nitride layer, or may have a multi-layered structureincluding the silicon oxide layer and the silicon nitride layer. Thebuffer layer 110 may prevent impurities in the base substrate 100 frombeing diffused upward. For example, due to the presence of the bufferlayer 110, it is possible to prevent moisture and oxygen from soakinginto a structure to be provided on the base substrate 100. The bufferlayer 110 may be formed to provide a planarized top surface.

After the formation of the buffer layer 110, the driving thin-filmtransistor TRd may be formed on the buffer layer 110. For example, thedriving thin-film transistor TRd may include the gate electrode GE, thesemiconductor active layer SA electrically separated from the gateelectrode GE, and the source and drain electrodes SE and DE connected tothe semiconductor active layer SA.

According to exemplary embodiments of the present disclosure, thedriving thin-film transistor TRd may be formed by performing steps to bedescribed below.

Firstly, a gate conductive layer (not shown) may be formed on the bufferlayer 110 and may be patterned to form the gate electrode GE.

After the formation of the gate electrode GE, the gate insulating layer120 may be formed to cover the gate electrode GE. The gate insulatinglayer 120 may include at least one of silicon oxide (SiO₂) or siliconnitride (SiNx).

After the formation of the gate insulating layer 120, the semiconductoractive layer SA may be formed on the gate insulating layer 120 to bepartially overlapped with the gate electrode GE. The formation of thesemiconductor active layer SA may include forming a semiconductor layer(not shown) on the gate insulating layer 120 and then pattering thesemiconductor layer.

The semiconductor active layer SA may include one of amorphous silicon(a-Si), poly silicon (p-Si), and oxide semiconductors. Further, thesemiconductor active layer SA may include the channel region, which isoverlapped with the gate electrode GE, and the source and drain regions,which are located at both sides of the channel region and doped withimpurities. According to exemplary embodiments of present disclosure,the oxide semiconductors may contain at least one of Zinc (Zn), Indium(In), Gallium (Ga), Tin (Sn), or mixtures thereof. For example, theoxide semiconductors may include indium-gallium-zinc oxide (IGZO).

After the formation of the semiconductor active layer SA, the sourceelectrode SE and the drain electrode DE may be formed to be connected tothe source region and the drain region, respectively. The formation ofthe source and drain electrodes SE and DE may include forming a dataconductive layer (not shown) to cover the semiconductor active layer SAand the gate insulating layer 120, and then, patterning the dataconductive layer. According to exemplary embodiments of presentdisclosure, the source electrode SE and drain electrode DE may be formedto be spaced apart from each other.

The data conductive layer may include one of copper, copper alloy,aluminum, and aluminum alloy.

Further, although not shown, an ohmic contact layer may be providedbetween the source region and the source electrode SE and between thedrain region and the drain electrode DE. The ohmic contact layer maycontribute to improve an electric connection property between the sourceregion and the source electrode SE and between the drain region and thedrain electrode DE.

After the formation of the source electrode SE and the drain electrodeDE, the protection layer 130 may be formed to cover the resultingstructure with the driving thin-film transistor TRd. The protectionlayer 130 may include at least one layer. For example, the protectionlayer 130 may include an inorganic protection layer and an organicprotection layer disposed on the inorganic protection layer. Theinorganic protection layer may include at least one of silicon oxide andsilicon nitride. Further, the organic protection layer may include atleast one of acryl, polyimide (PI), polyamide (PA), and benzocyclobutene(BCB). According to exemplary embodiments of present disclosure, theorganic protection layer may be transparent and flexible, and thus, itmay serve as a planarization layer reducing unevenness of an underlyingstructure.

Referring to FIGS. 4 and 5, after the formation of the protection layer130, the protection layer 130 may be patterned to form the contact holeCH partially exposing the drain electrode DE.

After the formation of the contact hole CH, a transparent conductivelayer (for example, including a transparent conductive oxide) may beformed on the protection layer 130 and then patterned to form the firstelectrode 140 and the auxiliary electrode 170 that are spaced apart fromeach other. The first electrode 140 may be connected to the drainelectrode DE via the contact hole CH. The auxiliary electrode 170 mayinclude the connection part CP and the non-connection part NCP. Theconnection part CP may refer to a region in contact with the secondelectrode 160, and the non-connection part NCP may refer to a region notin contact with the second electrode 160. In addition, when measured inthe direction perpendicular to a current flow, the auxiliary electrode170 may be formed in such a way that a width of the connection part CPis less than that of the non-connection part NCP.

The first electrode 140 and the auxiliary electrode 170 may include atransparent conductive oxide, having a work-function that is higher thana work-function of the second electrode 160. For example, the firstelectrode 140 may include one of indium tin oxide (ITO), indium zincoxide (IZO), aluminum zinc Oxide (AZO), gallium doped zinc oxide (GZO),zinc tin oxide (ZTO), gallium tin oxide (GTO), and fluorine doped tinoxide (FTO).

After the formation of the first electrode 140 and the auxiliaryelectrode 170, the pixel defining layer PDL may be formed to include thefirst opening OP1 partially exposing the first electrode 140 and thesecond opening OP2 partially exposing the auxiliary electrode 170.

The pixel defining layer PDL may include an insulating organic material.For example, the pixel-defining layer PDL may include at least one ofpolystylene, poly methyl methacrylate (PMMA), polyacrylonitrile (PAN),polyamide, polyimide, polyarylether, heterocyclic polymer, parylene,fluorine series polymer, epoxy resin, benzocyclobutene series resin,siloxane series resin, or silane resin.

Referring to FIG. 6, after the formation of the pixel defining layerPDL, an organic layer 150′ may be formed on the pixel defining layerPDL. The organic layer 150′ may be provided on the pixel defining layerPDL, the first electrode 140, and the auxiliary electrode 170.

The organic layer 150′ may include at least the emitting layer EML and,in general, may have a multi-layered structure. For example, the organiclayer 150′ may include the hole injection layer HIL, the hole transportlayer HTL, the emitting layer EML, the hole blocking layer HBL, theelectron transport layer ETL, and the electron injection layer EIL. Thehole transport layer HTL may have a high hole mobility and be configuredto suppress movement of electrons that are not combined in the emittinglayer EML, thereby increasing probability of recombination between holesand electrons. In the emitting layer EML, the injected electrons andholes may be re-combined with each other to emit light. The holeblocking layer HBL may be configured to suppress holes, which are notcombined with electrons in the emitting layer EML, from moving. Theelectron transport layer ETL may be configured to move electrons to theemitting layer EML efficiently.

Referring to FIG. 7, after the formation of the organic layer 150′, theorganic layer 150′ may be patterned to remove a portion of the organiclayer 150′ from a region adjacent to the connection part CP, therebyforming the organic pattern 150.

For example, after the formation of the organic layer 150′, an electricpower may be applied to the auxiliary electrode 170 to produce heat fromthe connection part CP. Since the width of the connection part CP isless than that of the non-connection part NCP, the heat may be locallyproduced from the connection part CP. According to exemplary embodimentsof present disclosure, the electric power may be applied in such a waythat a portion of the organic layer 150′ adjacent to the connection partCP can be evaporated or sublimed by the heat. Accordingly, the organiclayer 150′ may be patterned to form the organic pattern 150.

Referring to FIG. 8, after the formation of the organic pattern 150, thesecond electrode 160 may be formed on the organic pattern 150. Thesecond electrode 160 may be partially connected to the connection partCP. According to exemplary embodiments of present disclosure, theorganic layer 150′ may not be provided between the second electrode 160and the connection part CP, and thus, it is possible to improve anelectric connection property between the second electrode 160 and theconnection part CP.

In addition, the second electrode 160 may include at least one ofmaterials (e.g., Mo, W, Ag, Mg, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, Li, Ca,and alloys thereof), whose work-function is smaller than the firstelectrode 140.

After the formation of the second electrode 160, an encapsulatingprocess may be further performed to fabricate the organic light-emittingdisplay device.

Exemplary embodiments of the present disclosure are also described withreference to FIG. 9. For concise description, a previously describedelement may be identified by a similar or identical reference numberwithout repeating a description thereof.

FIG. 9 is a sectional view illustrating an organic light-emittingdisplay device according to other exemplary embodiments of the presentdisclosure.

Referring to FIG. 9, an organic light-emitting display device mayinclude the driving thin-film transistor TRd and the organiclight-emitting device OLED disposed on the base substrate 100. Theorganic light-emitting device OLED may be connected to the drivingthin-film transistor TRd.

The driving thin-film transistor TRd may be disposed over the basesubstrate 100. The driving thin-film transistor TRd may include the gateelectrode GE, the semiconductor active layer SA electrically separatedfrom the gate electrode GE, and the source and drain electrodes SE andDE connected to the semiconductor active layer SA.

The protection layer 130 may be provided on the resulting structure withthe driving thin-film transistor TRd. For example, the protection layer130 may be formed to cover the driving thin-film transistor TRd and mayhave a contact hole CH partially exposing the drain electrode DE.

The organic light-emitting device OLED and the auxiliary electrode 170may be provided on the protection layer 130.

The organic light-emitting device OLED may include the first electrode140 connected to the drain electrode DE, the organic pattern 150disposed on the first electrode 140, and the second electrode 160disposed on the organic pattern 150.

The auxiliary electrode 170 may be provided at the same layer as thefirst electrode 140. For example, the auxiliary electrode 170 may beprovided on the protection layer 130 to be spaced apart from the firstelectrode 140. The auxiliary electrode 170 may be partially exposed bythe second opening OP2 of the pixel defining layer PDL.

The auxiliary electrode 170 may include the connection part CP and thenon-connection part NCP. The connection part CP may refer to a region incontact with the second electrode 160, and the non-connection part NCPmay refer to a region not in contact with the second electrode 160. Insome cases, the connection part CP and the non-connection part NCP mayhave different resistances from each other. For example, the connectionpart CP may have a resistance higher than that of the non-connectionpart NCP.

The organic material 150 may not be provided between an auxiliaryelectrode 170 and a second electrode 160 thereby improving an electricconnection property between the auxiliary electrode 170 and the secondelectrode 160. Accordingly, it is possible to prevent a voltage dropfrom occurring in the second electrode 160.

In some cases, the formation of the organic light-emitting displaydevice may include generating heat from the auxiliary electrode 170 toremove an organic material formed on the auxiliary electrode 170. Forexample, electric power may be applied to the auxiliary electrode toproduce heat in the connection part CP of the auxiliary electrode 170.Organic material of the organic layer 150 may be removed from theconnection part CP due to the heat. Accordingly, it is possible to omitan additional step of removing the organic material.

It will be apparent to those skilled in the art that variousmodifications and variation can be made in the present disclosurewithout departing from the spirit or scope of the disclosed subjectmatter. Thus, it is intended that the present disclosure cover themodifications and variations of the disclosed subject matter providedthey come within the scope of the appended claims and their equivalents.

What is claimed is:
 1. A method of fabricating an organic light-emittingdisplay device, the method comprising: forming a thin-film transistor ona base substrate; forming a first electrode connected to the thin-filmtransistor and an auxiliary electrode spaced apart from the firstelectrode, the auxiliary electrode comprising a connection part and anon-connection part; forming a pixel defining layer, the pixel defininglayer exposing portions of the first electrode and portions of theconnection part; forming an organic layer on the first electrode, theconnection part, and the pixel defining layer; patterning the organiclayer to form an organic pattern; and forming a second electrode on theorganic pattern and the pixel defining layer, wherein forming theorganic pattern comprises: applying an electric power to the auxiliaryelectrode to produce heat from the connection part; and removing aportion of the organic layer adjacent to the connection part using theheat, wherein the connection part and the non-connection part of theauxiliary electrode are arranged along a lengthwise direction, andwherein a width of the connection part along a widthwise directionperpendicular to the lengthwise direction is less than a width of thenon-connection part along the widthwise direction.
 2. The method ofclaim 1, wherein the first electrode and the auxiliary electrode areformed on the same layer.
 3. The method of claim 1, wherein the organicpattern contacts the first electrode and does not contact the auxiliaryelectrode.
 4. The method of claim 1, wherein the width of the connectionpart is less than the width of the non-connection part when measured ina direction perpendicular to a current flow.